Improved



tluitrll tapes- JAMES JERVIS, 0F BALTIMORE, MARYLAND.-

Letters Patent No. 95,804, (lated October 12, 1869.

IMPROVE!) FILE-CUTTING MACHINE.

The Schedule referred to in these Letters Patent and making part of the` same.

, regulator, whose office is to keep the shape steady on the bed-piece at the time of the stroke of the chisel,

as well as to perform other functions.

It will also be seen .that the chisel, when the shape is moved rrnder it, always strikes it, and makes its cut at the same angle, and that, although the chisel may be set at different angles for diiferent files, yet its motion, for the same file, is always at the same angle.

n As a consequence of this, when the shape, or file before the teeth are cut, tapers, lwhich all tiles do more or less, the teeth, when cut by the blows of the chisel, are sharper on one part of the face, or edge, as the case may be, than on the others.

In hand-cut files, the workman prevents this result by changing the angle of his chisel, as it passes over the 'face ofthe shape; and the object of my invention is to produce the saure effect by machinery that is the result of the intelligence and skill of the workman.

The chisel of the improvement patented as aforesaid, passes through a cross-head or guide, and my invention operates on this cross-head through the regulator, which, resting at all times on the shape during the process of cutting, has a vertical movement, depending on the amount of taper in thickness of the shape.

This vertical movement in my former patent is always in a night line, whether the chisel moves perpendicular to or at an angle with the horizon.

In my present improvement, I make the taper of the shape, as it raises or lets fall the regulator, change the angle of the chisel, by causing the cross-head to rise or fall in the arc of a circle, instead of a straight line.

lu the accompanying drawings- Figure I represents what I here term the crosshead, carrying the chisel lS in its socket B, and the regulator E.

FigureII is a sectional view of the cross-head, showing the chisel in its.` socket, and the socket in its sleeve.

Figure III represents the inside of one of the jaws, in which the cross-head moves under the influence of the taper of the shape, which forces it up or lets it down as the shape maybe entering or' leaving the machine.

In my former patent, this upward and downward motion was in a right line, and always at the saine angle, as already said.

It is now in a curved line, the rirn C', Fig. III, iitting and moving in the. groove C,"Fig. I, pr'oducing this effect.

'Ilie centres of the ares of circles C and C', are shown in the drawing at p )1 p, which are also the centres of the dotted arcs at 1v w, Figs. I and I l, where is seen the point or edge of the chisel and the regulator.

It is apparent, now, on inspelltion, that when the cross-head carrying the chisel and regulator,ascends with a movement given to it by the curved rinr and groove C and C', the chisel and regulator' must move along the dotted line w, changing as the chisel moves, its angle to the horizon, and consequently the sharpness of the tooth cut by the blow of the chisel on the shape, the result being uniformity in the sharpness of the teeth on every portion of the tile. v

In addition to what has already been described, Fig. I shows the slotsand nuts at L L, which permit the position of the guides, in which the chisel itself moves in giving its blow to be changed according to the sharpness required for the tooth of the particular description of file which is being cut; and there is also shown the spring at P, one end of which restson the cross-head, and the other on a bar, Y, shown in' section, connecting the jaws, in which the cross-head moves, the degree of pressure which the springs, one only of which is shown, give to the cross-head, being regulated by the nut and screw shown in Fig. I.

In Fig. II is shown the lever I l', the dotted ontl line representing it down with the regulator pressed upon the shape, as in the process of cutting.

IVhen the lever is raised, the action of the spring M lifts the regulator, and'thc frle may be removed.

m is a catch, with a slot, pressed upward by thc spring 'n when the' lever is down to keep the lever in place.

To release the lever', the handle o is pressed down, so as to let go the catch.

Ihe thumb-screw, represented at X, Figs. I and-II, when screwed down upon the bar Y, makes the crosshead immovable, while the regulator is permitted to` move freely up and down when Jthe lever is raised.

Then the lever is lowered, which has the effect of confining the regulator to the cross-head, 4and the thumb-screw is loosened, the regulator' moving over the taper of the shape, raises or lowers the cross-head,

and so changes the angle ofthe. chisel in giving itsI blow.

I call the cross-head here described a rotating crosshead.

What I claim as new, and desire to secure by Letters Patent, is-f- The mechanism here described, whereby the move ment ofthe regulator on the shape is made to change the angle of the chisel, so as to maintain the sharpness of the tooth the same in every part of the the shape, isto impart a movement to the crosshead corresponding to the taper of the shape.

JAMES JERVIS. file.

Also, the combination of a cross-head, having a -l/Vitnesses: rotating motion, substantially as described, with a JOHN H. B. LA TROBE,

chisel and regulator, whose agency, besides steadying GEO. A. FREDERICK. 

